System and method of pipeline data access to remote data

• US 6,957,219 B1
• Filed: 11/15/2001
• Issued: 10/18/2005
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Raman, Balan Sethu, Lin, Yun
• Primary Examiner(s): Ali, Mohammad
• Application Number:
  US10/003,137
• Time in Patent Office: 1,433 Days
• Field of Search: 707 1- 10, 707100-1041, 707200-205, 709/203, 709/217, 709/239
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A pipeline I/O mechanism in a network redirector that breaks up large files into sections, and sends write (or read) requests for each section in a pipeline fashion to a network file server, without waiting for a response for a previously-sent section. The pipeline I/O mechanism tracks the returned status of each section for which a request was made, so that success or failure of the request is determined as a whole. The pipeline I/O system and method dramatically increase the performance of network remote I/O operations, particularly with file write operations directed to a file on a network file server.

Claims

1. In a computer network, a method comprising:

at a client-side redirector, receiving a write or read request directed to a file on a remote network server, the write or read request directed to communicating an amount of file data that exceeds a maximum buffer size allowed for communicating file data in a request to the remote server;

logically separating the write or read request into a plurality of file section requests that each do not exceed the maximum buffer size;

sending each of the file section requests to the remote network server, at least one file section request being sent without awaiting a status response resulting from a previously sent file section request;

tracking status information for the file section requests; and

if the status information from the file section requests indicates success, returning a success indication in response to the write or read request.

2. The method of claim 1 further comprising, receiving the maximum buffer size from the remote server.

3. The method of claim 1 wherein tracking the status information comprises, receiving a response corresponding to one of the file section requests, evaluating the response, and when the response indicates success, accounting for the successful response.

4. The method of claim 3 further comprising, allocating an array of entries for the plurality of file section requests, wherein each file section request corresponds to an entry in the array, and wherein accounting for the successful response includes, determining an entry in the array corresponding to the successful response, and adjusting the entry to indicate success.

5. The method of claim 3 wherein determining an entry in the array corresponding to the successful response comprises, associating a value with each file section request that differentiates that file section request from other file section requests, and determining the value by evaluating the successful response.

6. The method of claim 5 wherein the array comprises a bitmap, and wherein adjusting the entry to indicate success comprises clearing at least one bit to zero, such that the status information from the file section requests indicates success when the entire bitmap equals zero.

7. The method of claim 5 further comprising, calculating a size for the array based on the amount of file data.

8. The method of claim 1 further comprising, determining that the write or read request exceeds the maximum buffer size allowed.

9. A computer-readable medium having computer-executable instructions for

receiving, at a client-side redirector, a write or read request directed to a file on a remote network server, the write or read request directed to communicating an amount of file data that exceeds a maximum buffer size allowed for communicating file data in a request to the remote server;

logically separating the write or read request into a plurality of file section requests that each do not exceed the maximum buffer size;

sending each of the file section requests to the remote network server, at least one file section request being sent without awaiting a status response resulting from a previously sent file section request;

tracking status information for the file section requests; and

if the status information from the file section requests indicates success, returning a success indication in response to the write or read request.

10. In a computer network having a file server, a client-side system, comprising:

an application program that issues an I/O request corresponding to a file on a file server, the I/O request corresponding to an amount of file data that exceeds an allowed amount that can be exchanged with the file server in a single request; and

a network redirector having an associated pipeline I/O mechanism, configured to;

1) receive information corresponding to the I/O request;

2) send a plurality of sectioned I/O requests to the network server to satisfy the I/O request received at the application, at least one of the requests sent without awaiting status information from the server for a previously sent request, and each sectioned I/O request corresponding to file data that does not exceed the allowed amount;

3) track status information for each of the sectioned I/O requests; and

4) determine a status to return to the application program based on the tracked status information.

11. The system of claim 10 wherein the status to return to the application corresponds to an error if the status information of any one of the sectioned I/O requests indicates an error.

12. The system of claim 10 wherein the status to return to the application corresponds to a success if the status information of every one of the sectioned I/O requests indicates a success.

13. The system of claim 10 wherein the network redirector tracks the status information by updating an entry corresponding to a sectioned I/O request in an array when the status information for the sectioned I/O request is known.

14. The system of claim 13 wherein the array comprises a bitmap.

15. The system of claim 10 wherein the redirector and file server communicate via protocol comprising SMB.

16. The system of claim 10 wherein the redirector and file server communicate via protocol comprising CIFS.

17. In a computer network, a method comprising:

at a client-side redirector, receiving a write request to write file data to a file on a remote network server, the write request indicating an amount of data to be written that exceeds a maximum size allowed per request by the remote server;

logically separating the write request into a plurality of partial write requests that each do not exceed the maximum buffer size;

allocating a data structure containing an entry for each file section request;

sending each of the file section requests to the remote network server, at least one request being sent without awaiting a status response that results from a previously sent request;

evaluating responses from the file system, and for each successful response that corresponds to a partial write request, updating the array at a location therein that corresponds to that file section request; and

returning a success indication when the array indicates that each of the partial write requests was successful.